Method of constructing tunnels.



PATENTED mmv; 1904.

A-. IB.GLARK-. METHOD OF GONSTRUGTINGV. TUNNELS.

APPLICATION FILED APR. 21, 1902.

H0 MODEL.

TH: Nnnivs PETERS ccL. PNOTO-LITHQ. wnsmnumu, n. cy

Patented June 7, 1904.

PATENT OFFICE.

AMASA B. CLARK, OF NEW YORK, N. Y.

METHOD OF CONSTRUCTING TUNNELS.

SPECIFICATION forming part of 'LettersPatent No. 761,658, dated June 7, 1904. Application filed April 21., 1902. Serial No. 103,885. (No model.)

ing underground tunnels and supporting the same in soft ground and is directed specifically to a method of forming the support.

The object of my invention i'stoprovide a method of construction whereby a tunnel which would otherwise be in an unstable condition may be made secure with a minimum expenditure of. time and money through the I provision of a support of a firm,.compact, and lasting character.

My invention also involves various other improvements in the method of constructing tunnels, as hereinafter described, and pointed out in the appended claims.

The constructionand maintenance of subterranean or subaqueous driven tunnels have hitherto been attended by serious obstacles and difliculties, due not only to the disadvantages of working at a depth below water-level, but mainly to the 'impraoticability of reinforcing the tunnel, so that it may be depended upon to resist the complex forces which act against it and tend to distort it. Among such forces may be mentioned those due to the differences in weight of the tunnel, variations in its buoyancy, the vibrations of passing traffic, and likewise the bodily movement of the surrounding material or silt, which in riverbeds is often likely to have a gradual downstream movement. It' is especially difficult to resist these distorting tendencies during the constructionor driving of a tunnel,'and various means have often been I proposed for preventing themsuch, for example, as by injecting grout or temporarily congealing the material immediately in advance of the tunnel. These methods, however, are expensive and'also insecure, especially the former, inasmuch as a mixture of grout and silt will not set. By the method of construction herein explained, whereby the tunnel-lining is secured in place as it advances and the surrounding material more or less compacted about it,

these injurious tendencies are readily overcome and with a minimum of expense.

My method is briefly as follows: Having constructed in the soft ground a tunnel by any of the methods now, employed and well knownsuch, for example, as by forwarding a shield through the soft ground and erecting behind the same a lining of metal, concrete, brick, wood, or the likeI make apertures in the lining and from within the tunnel force piles through the apertures into the surrounding soft ground as the tunnel advances to an extent, as regards both number and size ofthe piles, sufficient to hold the lining in place against the forces tending to displace it,whereupon I attach the inner ends-of these piles to the lining by any suitable means of attachment, so that tensile, compressive, and shearground With such a tunnel located therein.

Fig. 2 represents a cross-sectional view of the tunnel on a larger scale. Fig. 3 is a detail on a still larger scale, showing the connection of the lining and piles.

. Similar reference-letters indicate similar parts throughout the several views.

Asmost river-beds are composed in part of silt and as this is the most natural point for the adoption of my method of construction, I have shown my tunnel as lying under a river A, under which is a layer of silt B, under that a stratum of sand (3, and below this stratum of sand the bed-rock D. The tunnel E lies in silt B and has projecting from it the piles F, some of which, as G, may be put down to bed-rock, if desired. As it is obviously impossible to drive an ordinary pile from Within a tunnel of the usual size, I propose to employ sectional piles, either tubular or solid, which can be forced sectionby section to the desired position by hydraulic jacks or rams, by screws, or in the case of the tubular pile by a suitable power-hammer,

if the pile is so directed that the hammer will remain against the part of the pile which it strikes-that is, if the pile is directed downward, so that gravity will keep the hammer against the top surface of the point of the pile. In certain materials the introduction of the piles into the ground immediately surrounding the tunnel may be facilitated by the use of a jet of liquid cement or other fluid or semifluid substance. By employing a hollow pile a pipe may be run through the same and the fluid conducted therethrough to the point of the pile, from which it may issue with any force desired. If cement grout be used, the density of the material surrounding the pile will thereby be increased. After the pile has been driven to the extent desired the pipe may be removed and the hollow interior filled with cement or hydraulic concrete. The inner end of the last section is to be joined to the lining, preferably by a connection such as will resist tensile, compressive, and shearing strains. The piles will therefore serve as well to keep the tunnel from rising through its buoyancy as to prevent it from sinking or from moving laterally. The annular space between the pile andthe opening in the lining can be kept closed during the act of driving by means of ropestrands, oakum, or other suitable material. When the pile is ready to be attached, a fillerring can be placed around the opening on the inner side of the lining, a cap placed on top of the same and bolted to the lining. An an chor should be embedded in the concrete filling of the pile and firmly attached to this cap, by means of which construction the lining and the pile will be securely connected. I prefer to employ a metal lining, and, as shown inFig. 3, this will be made of plates provided with flanged apertures. The tunnel being driven by any of the usual methods-as, for instance, by forwarding a shield-these plates are placed in position behind the shield to form the lining, which is thus extended by successive sections through the ground, and the piles are preferably driven through the apertures already provided as fast as the sections are secured in position. It is obvious, though, that the apertures may be madeafter the lining has been put in place. In Fig. 3 the lining E is provided with a flange H, surrounding the aperture I, the filler-ring K being placed on the flange and the'cap L being placed abovethat, the cap beingheld down by an anchor-boltM, embedded in the concrete filling N, a screw-nut O being placed above the cap on the end of the bolt. With such construction it is evident that any force tending to raise the tunnel will be transmitted through the anchor-bolt to the pile, which in turn will be prevented from moving by the friction of the compacted earth about it. A tendency of the tunnel to sink will also be resisted by the friction of the pile against the compacted earth. In order to provide more surely against lateral motion of the tunnel, the piles may be driven laterally and even upward from within the lining, as seen in Fig. 2. If an endwise movement of the tunnel be feared, certain of the piles may be driven at an angle in a direction to resist such end wise movement, as seen in Fig. 1, the fact being kept in view that the pile may be driven on any line not making a small angle with the axis of the tunnel. The piles may be arranged in groups of two or more. In certain instances where bed rock may be readily reached it is of course feasible to extend groups of piles or even single piles down to the bed-rock, so as to make available any increase in security due to such an extension. Such aeonstruction is shown by the pile G in Fig. 1.

In some instances I may find it desirable. when operating with a shield to compact the earth about the shield by driving piles through apertures provided in the shield in the same manner as though the permanent lining were in place and thereafter, when the shield has been moved forward, setting up the permanent lining and attaching the same, as before stated, to thepiles already driven. My method is thus in no wise altered by the fact that the compacting of the earth is first performed about a temporary lining which is thereupon removed and a permanent lining inserted.

I am aware that tunnels and pi pcs have heretofore been built in the construction of which the linings or tubes were sunk into position and then secured by piles driven from within the lining into the river-bottom or :uljacent material; but the present invention is essentially different from all of these prior methods in that the piles are driven from within the lining, which may be done as fast as the tunnel is advanced or extended through the soil, so that the rear of the tunnel maybe com pletely formed before the forward end has reached its destination, thus expediting the withdrawal of the excavationsand enhancing the safety of the work.

Having described my invention, what I claim as new, and what I desire to secure by Letters Patent, is-

1. A method of constructing tunnels which consists in advancing through soft ground a lining, passing a plurality of piles, from within the lining into the surrounding material and securing the inner ends of said plurality of piles to the lining so as to resist tensile, compressive and shearing strains, substantially as described.

2. A method of constructing tunnels which consists in successively extending a tunnellining, section by section, into soft ground, and supporting said successive extensions, as they are erected, by passing piles from within the lining into said ground, substantially as described.

3.- A method of constructing tunnels which consists in successively extending a tunnellining, section by section, into soft ground, passing piles from within the successive extensions of'the lining, as they are erected, into the surrounding material and attaching the inner ends of said piles to the lining so as to resist tensile, compressive and shearing strains, substantially as described.

4:. A method of constructing tunnels which consists in successively extending a tunnellining, section by section, into soft ground, providing said successive extensions with apertures, passing piles through said apertures into the surrounding ground, and securing the inner ends of said piles to the lining so as to resist tensile, compressive and shearing strains, substantially as described.

5. A method of constructing driven tunnels, which consists in erecting in soft groundalining provided with apertures, passing sectional piles, section by section, from within the lining, through said apertures, to an extent, as

regards nuinber'and size of piles, suflicient to hold the lining in place against forces tending to displace it, and securely attaching the inner ends of the innermost pile-sections to the lining, so as to resist tensile, compressive and shearing strains, substantially as described.

7. Amethod of constructing tunnels, which consists in constructing in soft ground a lining provided w1th apertures, passing hollow piles from within the lining,through said apertures, to an extent, as regards number and size of piles, suflicient to hold the lining in place against forces tending to displace it,

- filling said piles with concrete and attaching a cap to the lining and to the concrete, thereby securing the pile to the lining so as to resist tensile, compressive and shearing strains, substantially as described.

In testimony whereof I have hereunto signed my name, in the presence of two subscribing witnesses, this 17th day of April, 1902.

) AMASA B. CLARK.

Witnesses: V THEODORE T. DORMAN,

ALEDA C. BAYLIS. 

